The Heat Tracing Technologies for Winter Rail Heating | nVent

During the winter months, snow and ice buildup on rail tracks and overhead contact wires can cause major disruptions to railway operations. Recent winter weather has truly put winter rail heating to the test, as extreme conditions ripple across rail pathways in North America. For passengers, icy train platforms can cause major safety concerns. However, there are a variety of winter rail heating solutions that can eliminate these costly problems.

Let’s take a look at the different types of heat tracing that can be utilized by the rail industry.

The Importance of Winter Rail Heating

While there are plenty of critical problems for rail operators during winter, there are a few that can lead to safety concerns and costly repairs.

• Switch Rail Heating: Snow and ice build-up on track switches can prevent proper alignment, which is a significant challenge to railway safety and reliability.
• Contact Rail Heating: The contact rail, or third rail, provides power that propel trains, making it a critical part of rail infrastructure that must be kept clear of snow and ice.
• Overhead Contact Wires: Many transit railways are powered by overhead contact wires situated over the track that must make clear contact with the train via an apparatus (pantograph) attached to its roof.

Self-Regulating Heating Technology

Self-regulating cables are designed to automatically react to ambient temperature and changes in temperature along the length of the cable. This allows the cable to vary power output and provide heat where it’s needed.

Self-regulating switch heating systems have many benefits, including:

• Safety: System temperature maxes out at 176° F/80° C, which makes it safe to the touch for personnel.
• Durability: Raychem self-regulating heating cables are rugged cables designed to withstand the vibration of significant rail traffic. As part of nVent switch heating system, the self-regulating heating cables are secured to the track with nVent ERICO rail clips, which are built to resist environmental corrosion. The cables can also be cut to length, reducing the time spent on installation.
• Energy-Efficient: Energy costs are lowered with self-regulating technology, as they eliminate wasted wattage consumption. Often, these cables are 30% more efficient than conventional alternatives.

nVent offers switch heating systems and contact rail heating systems that feature self-regulating heating cables, providing custom system design to meet the individual specifications of the end-user.

Constant Wattage Heating Technology

Constant wattage heating technology is characterized by a robust heating element that delivers constant heat irrespective of the ambient temperature. This solution reduces the power distribution costs at lower start-up temperatures and provides adequate heat at higher ambient temperatures.

nVent offers constant wattage heating systems for switches snow melting and overhead contact wire de-icing.

Constant wattage solutions offer benefits such as:

• Robust heating: For switch heating, the Flat MI constant wattage heating cable covers more surface area than conventional tubular heating rods, thereby resulting in better heat transfer. This not only melts the snow and ice faster but also results in lower heater temperatures improving the longevity of the product.
• Service Proven Solution: Constant wattage technology is a widely accepted heating technology that railways throughout the world use to prevent snow and ice-buildup on switches and overhead contact wires in demanding weather conditions.
• Energy-Efficient: Due to efficient heat transfer the power consumption for nVent constant wattage solutions is reduced by 40% compared to tubular heaters.

The constant wattage switch snow melting and overhead contact wire de-icing solutions can be custom designed for any rail project. In addition, nVent provides heating control solutions, including controller hardware and wired/wireless communications system, that allow for track side or remote control and monitoring of these heating systems.

Power Limiting Heating Technology

Power limiting heating technology combines the benefits of self-regulating technology and constant wattage technology. Power limiting cable consists of a heating element which has a positive temperature coefficient. For example, the wattage of the cable linearly decreases with the increasing ambient temperature. This technology allows for higher wattage of heating cable yet flexibility of installation due to its cut-to-length nature. Power limiting technology is commonly used for contact rail de-icing.

Benefits of power limiting technology:

• Flexibility of installation: The power limiting technology is cut-to-length technology and can be field terminated resulting in flexibility of installation.
• Energy-Efficient: The product is designed with a thermally conductive jacket and installed with fiberglass channel resulting in efficient heat transfer to the contact rail.
• Service Proven Solution: Power limiting heating technology is used for contact rail de-icing throughout the world.

nVent has successfully engineered thermal solutions for heat tracing and snow melting applications for people movers, rail cars, platforms and building infrastructure.

nVent Solutions for Rail and Transit

If you’re looking for rail solutions, now is a great time to start your research. Winter is in full swing, and only predicted to get colder, so implementing heat tracing technology now can reduce costs, and highlight safety at your operation.

nVent works hard to connect and protect critical systems and offers a full portfolio of rail solutions including the technology mentioned in this post. To learn more about nVent rail infrastructure heating solutions, visit our winter rail page located here.

If you’d like to dive into more rail-related topics and news, visit the nVent Rail Blog for monthly posts on global connection solutions for safer, more reliable railways.